With such expressivity, there is a risk in a big project of individuals conjuring wildly different mechanisms to express similar if not identical ideas, losing out on understandability and consistency. The solution is often a strong style guide that everyone must read and follow. If Rust ever makes it to the kernel, I hope such a guide is written...
Rust is "safe" and other languages are "unsafe". Haskell is "pure" while other language are "impure". Some macro systems are "hygienic" while others are "dirty". It is not an accident that the humpty dumpties (language designers) chose to use these particular terms for their semantic distinctions. It's useful for propaganda. The mind encounters a colloquial term and equivocates. This happens in both the critics and the evangelizers. Inferences drawn are then often unjustified.
I have a word in mind, but before that I would ask: what are some safety-critical systems written in Rust? If there are any, how big a role does Rust play in their safety properties? Is it much different from any other programming language?
I can already hear faint exclamations about the language's age, but are Rust programmers justified in putting forward claims about safety? Or do they shift to using the word in the sense of "fewer bugs in this particular class" (and nevermind any other effects the language may have on development).
Even if we take such a narrow and distorting view of "safety", we can look at, say, "The Power of Ten" and ask how does Rust use fare with each rule, and is it any more advantageous than other languages in use by safety-critical systems.
I don't blame this guy. It's the people who let the Barbarians in, because politics.
Sometimes gates need to be kept.